A National Cancer Institute of Canada Clinical Trials Group phase II study of eniluracil (776C85) and oral 5-fluorouracil in patients with advanced squamous cell head and neck cancer

Abstract

Background/Patients and methods: Thirty-two patients with recurrent head and neck cancer (HNC) following radiotherapy and/or surgery were treated with eniluracil (10 mg/m2) and 5-fluorouracil (5-FU) (1 mg/m2) (E5F) orally twice daily for 28 days followed by a seven-day treatment free period. Thirty-five-day cycles were repeated until disease progression, unacceptable toxicity or patient refusal. Doses were modified for toxicity. Standard toxicity and response criteria were used. Results: Thirty-two patients were accrued; thirty-two and twenty-eight patients were evaluable for toxicity and response, respectively. Twelve patients received three or more cycles of E5F. Drug related toxicities were usually grade 1-2 intensity and included lethargy, nausea or diarrhea (≥ 25% of patients), and anorexia, rash or itch, stomatitis or vomiting (12%-24% of patients). Hematologic toxicity was generally mild; two patients experienced grade 3-5 leukopenia or thrombocytopenia. No significant biochemical toxicity was seen. One patient was withdrawn (severe nausea and vomiting) and one patient died because of drug related toxicity (thrombocytopenia). In the final analysis there were one complete and four partial responses for a 15.6% overall response. Conclusions: E5F demonstrates activity in chemotherapy naïve patients with advanced HNC cancer with acceptable toxicity profile. Further investigation of E5F with other active agents is warranted in HNC.